Основні віхи розвитку української гірничої термінології

Ідеться про розвиток термінології й номенклатури гірничої справи, зокрема частково шахтобудування, яка активно розвивалася впродовж 20–З0-х рр. ХХ ст. Наголошено на спірних моментах в історії становлення цієї лексичної групи. Зроблено висновок про те, що нині гірнича термінологія української мови практично повністю унормована завдяки ретельній праці лексикографів та фахівців-гірників.The paper examines the ways mining terminology and nomenclature was developed. Special attention is drawn to the period of the 20th – 30th of the 20th century, when the term system was formed. The research focuses on disputable moments in the history of lexical group development; it concludes that mining terminology is normalized in the present-day Ukrainian language thanks to the careful work of lexicographers and mining specialist

RXTE observations of the first transient Z source XTE J1701-462: shedding new light on mass accretion in luminous neutron star LMXBs

(Abridged) We report on ten weeks of RXTE observations of the X-ray transient XTE J1701-462. Comparisons with other sources suggest it had all the characteristics of the neutron star Z sources (the brightest persistent neutron star LMXBs). These include Z tracks in X-ray color diagrams and typical variability components detected in the power spectra. XTE J1701-462 is the first transient Z source and provides unique insights into mass accretion rate (Mdot) and luminosity dependencies in neutron star LMXBs. As its overall luminosity decreased, we observed a switch between two types of Z-source behavior, with most of the branches of the Z-track changing their shape and/or orientation. We interpret this switch as an extreme case of the longterm changes seen in the persistent Z sources and suggest that these result from changes in Mdot. We also suggest that the Cyg-like Z sources (Cyg X-2, GX 5-1, and GX 340+0) might be more luminous (> 50%) than the Sco-like Z sources (Sco X-1, GX 17+2, and GX 349+2). Adopting a possible explanation for the behavior of kHz QPOs, which involves a prompt as well as a filtered response to changes in Mdot, we propose that changes in Mdot can explain both movement along the Z track and changes in the shape of the Z track. We discuss some consequences of this and consider the possibility that the branches of the Z will evolve into the branches observed in the X-ray color diagrams of the less luminous atoll sources, but not in a way that was previously suggested.Comment: Accepted for publication in ApJ, 11 page

Tracking of fluorescently labeled polymer particles reveals surface effects during shear-controlled aggregation

Surface chemistry is believed to be the key parameter affecting the aggregation and breakage of colloidal suspensions when subjected to shear. To date, only a few works dealt with the understanding of the role of the physical and chemical properties of the particles’ surface upon aggregation under shear. Previous studies suggested that surface modifications strongly affect polymer particles’ adhesion, but it was very challenging to demonstrate this effect and monitor these alterations upon prolonged exposure to shear forces. More importantly, the mechanisms leading to these changes remain elusive. In this work, shear-induced aggregation experiments of polymer colloidal particles have been devised with the specific objective of highlighting material transfer and clarifying the role of the softness of the particle’s surface. To achieve this goal, polymer particles with a core–shell structure comprising fluorescent groups have been prepared so that the surface’s softness could be tuned by the addition of monomer acting as a plasticizer and the percentage of fluorescent particles could be recorded over time via confocal microscopy to detect eventual material transfer among different particles. For the first time, material exchange occurring on the soft surface of core–shell polymer microparticles upon aggregation under shear was observed and proved. More aptly, starting from a 50% labeled/nonlabeled mixture, an increase in the percentage of particles showing a fluorescent signature was recorded over time, reaching a fraction of 70% after 5 h

The statistical properties of solar wind temperature parameters near 1 AU

We present a long-duration ($\sim$10 years) statistical analysis of the temperatures, plasma betas, and temperature ratios for the electron, proton, and alpha-particle populations observed by the \emph{Wind} spacecraft near 1 AU. The mean(median) scalar temperatures are $T{\scriptstyle_{e, tot}}$ $=$ 12.2(11.9) eV, $T{\scriptstyle_{p, tot}}$ $=$ 12.7(8.6) eV, and $T{\scriptstyle_{\alpha, tot}}$ $=$ 23.9(10.8) eV. The mean(median) total plasma betas are $\beta{\scriptstyle_{e, tot}}$ $=$ 2.31(1.09), $\beta{\scriptstyle_{p, tot}}$ $=$ 1.79(1.05), and $\beta{\scriptstyle_{\alpha, tot}}$ $=$ 0.17(0.05). The mean(median) temperature ratios are $\left(T{\scriptstyle_{e}}/T{\scriptstyle_{p}}\right){\scriptstyle_{tot}}$ $=$ 1.64(1.27), $\left(T{\scriptstyle_{e}}/T{\scriptstyle_{\alpha}}\right){\scriptstyle_{tot}}$ $=$ 1.24(0.82), and $\left(T{\scriptstyle_{\alpha}}/T{\scriptstyle_{p}}\right){\scriptstyle_{tot}}$ $=$ 2.50(1.94). We also examined these parameters during time intervals that exclude interplanetary (IP) shocks, times within the magnetic obstacles (MOs) of interplanetary coronal mass ejections (ICMEs), and times that exclude MOs. The only times that show significant alterations to any of the parameters examined are those during MOs. In fact, the only parameter that does not show a significant change during MOs is the electron temperature. Although each parameter shows a broad range of values, the vast majority are near the median. We also compute particle-particle collision rates and compare to effective wave-particle collision rates. We find that, for reasonable assumptions of wave amplitude and occurrence rates, the effect of wave-particle interactions on the plasma is equal to or greater than the effect of Coulomb collisions. Thus, wave-particle interactions should not be neglected when modeling the solar wind.Comment: 23 pages, 3 figures, 6 tables, submitted to Astrophys. J. Suppl. on Jan. 30, 201

The Physicist's Guide to the Orchestra

An experimental study of strings, woodwinds (organ pipe, flute, clarinet, saxophone and recorder), and the voice was undertaken to illustrate the basic principles of sound production in music instruments. The setup used is simple and consists of common laboratory equipment. Although the canonical examples (standing wave on a string, in an open and closed pipe) are easily reproduced, they fail to explain the majority of the measurements. The reasons for these deviations are outlined and discussed.Comment: 11 pages, 10 figures (jpg files). Submitted to European Journal of Physic

Membrane permeation of arginine-rich cell-penetrating peptides independent of transmembrane potential as a function of lipid composition and membrane fluidity

Cell-penetrating peptides (CPPs) are prominent delivery vehicles to confer cellular entry of (bio-) macromolecules. Internalization efficiency and uptake mechanism depend, next to the type of CPP and cargo, also on cell type. Direct penetration of the plasma membrane is the preferred route of entry as this circumvents endolysosomal sequestration. However, the molecular parameters underlying this import mechanism are still poorly defined. Here, we make use of the frequently used HeLa and HEK cell lines to address the role of lipid composition and membrane potential. In HeLa cells, at low concentrations, the CPP nona-arginine (R9) enters cells by endocytosis. Direct membrane penetration occurs only at high peptide concentrations through a mechanism involving activation of sphingomyelinase which converts sphingomyelin into ceramide. In HEK cells, by comparison, R9 enters the cytoplasm through direct membrane permeation already at low concentrations. This direct permeation is strongly reduced at room temperature and upon cholesterol depletion, indicating a complex dependence on membrane fluidity and microdomain organisation. Lipidomic analyses show that in comparison to HeLa cells HEK cells have an endogenously low sphingomyelin content. Interestingly, direct permeation in HEK cells and also in HeLa cells treated with exogenous sphingomyelinase is independent of membrane potential. Membrane potential is only required for induction of sphingomyelinase-dependent uptake which is then associated with a strong hyperpolarization of membrane potential as shown by whole-cell patch clamp recordings. Next to providing new insights into the interplay of membrane composition and direct permeation, these results also refute the long-standing paradigm that transmembrane potential is a driving force for CPP uptake